DESCRIPTION: The investigators plan to develop a device for stereotaxically implanting cells or microinjection of pharmacologic or trophic factors to deep brain sites. While other injection systems already exist, this system would be unique in several ways. The primary difference is the diameter of the injection cannula portion of the device. The device would also allow delivery at an angle to the primary cannula tract and could be used for electrophysiological recordings as well. PROPOSED COMMERCIAL APPLICATION: The proposed device would be sold to neurosurgeons as a reuseable stereotaxic carrier and a disposable microinjector needle. It would be used initially primarily for Parkinson's disease to make cell injections, and later for neurosurgery for other diseases where an accurately place set of small volume injections in brain would have therapeutic effect.